Pathology Flashcards
what is osteoporosis
reduced bone density and increased porosity
less than 2.5 SD below peak mean value of young adults of same race and sex
what is osteopenia
intermediate osteoporosis where <1-2.5 SD below peak mean value of young adults same sex and race
true/false - bone density loss is physiological?
true - osteoblastic activity begins to decrease around 30
why is osteoporosis more common in females
post menopause has less protective oestrogen so there is increased osteoclastic activity
causes of postmenopause primary osteoporosis and types of fracture
early menopause smoking lack exercise poor diet colles fracture and vertebral insufficiency
causes of osteoporosis of old age and types of fracture
reduced vitamin D
chronic disease
inactivity
femoral neck fracture and vertebral fracture
causes of secondary osteoporosis
steroid use chronic disease alcohol abuse malnutrition hyperthyroidism/hyperparathyroidism
what is the purpose of bisphosphonates
reduce osteoclastic absorption
what is zoledronic acid
IV annual bisphosphonate
action of desunomab?
reduces osteoclastic resorption
action of strontium in osteoporosis
increases osteoblast replication and reduces resorption
true/false - HRT is the best first line management for post menopause osteoporosis
false - bisphosphonates are as HRT has raised risk of breast and endometrial cancer as well as DVT
what is osteomalacia?
qualitative defect of bone leading to abnormal softening due to deficient mineralisation of calcium and phosphorus
causes of osteomalacia
inadequate sunlight exposure malabsorption malnutrition vitamin D resistance chronic kidney disease long term anticonvulsant use
symptoms of hypocalcaemia
parasthesiae muscle cramp irritable fatigue seizure brittle nails
what would you see on biochemistry with osteomalacia
low serum Ca and phos
high alk phos
what would you see on x rays of osteomalacia
pseudofracture of pubic rami, prox femora, ulna, ribs
causes of primary hyperparathyroidism
benign adenoma
malignant neoplasia
hyperplasia
symptoms of hyperparathyroidism
stones bones groans moans thrones psychiatric overtones
what is secondary hyperparathyroidism caused by
hypocalcaemia - causes overproduction of PTH
most common benign bone tumour/
osteochondroma
how does osteochondroma appear?
bony outgrowth with cartilagenous cap
true/false - there is a 2% chance of malignant transformation with osteochondroma
false - it is <1%
what is enchondroma and how does it appear
intramedullary and metaphyseal cartilagenous tumour by failed enchondral ossification
lucent and partly sclerotic
what bones is enchondroma more common in
femur, humerous, tibia, small bones hands and feet
what is an aneurismal bone cyst and what bones is it more common in
lots of chambers filled with blood/serum due to arterovenous malformation
long bones, flat bones, vertebra
what is a simple bone cyst and where may it be found
cavity filled cyst in bone proximal humerous or femur in metaphysis
true/false - simple bone cysts and aneurismal bone cysts both cause pathological fracture
true
what is a giant cell tumour and in what bones may it be found
benign tumour involving epiphysis extending to subchondral bone
knee and distal radius but also pelvis, spine and long bones
true/false - giant cell tumour can metastasise to lung
true - but it is still benign
what is fibrous dysplasia
genetic mutation in adolescents where there is lesions of fibrous tissue and immature bone
extensive fibrous dysplasia of the femur may cause ___
shepherds crook deformity
describe how an osteoid osteoma appears
immature bone surrounded by sclerotic halo
in what bones is an osteoid osteoma more common
proximal femur, diaphysis long bones and vertebrae
how would a malignant lesion appear on x ray
cortical destruction
periosteal reaction
new bone formation
extension into soft tissue
what bones does osteosarcoma affect and how does it spread
knee, proximal femur, proximal humerous, pelvis
haematogenous
true/false - osteosarcoma is responsive to adjuvant therapy
true
what age group does chondrosarcoma affect, what bones does it affect, what is it responsive to, fast or slow to metastasise
older age of around 45
pelvis or proximal femur
not responsive to radiotherapy or adjuvant
slow to metastasise
fibrosarcoma is more commmon in who?
fibrous dysplasia, pagets, post radiation
what is ewings sarcoma, what age, what does it respond to
malignant tumour of primitive cells in marrow
10-20
chemo and radiotherapy
surgery for primary malignant bone tumours involves resection with what cm margin
3-4 cm
metastatic breast cancer is blastic/lytic and survival is?
blastic or lytic
24 months
metastatic lung cancer is blastic/lytic and survival is
lytic
6 months
metastatic prostate cancer is blastic/lytic and survival is
sclerotic (blastic)
45% survive 1 year
metastatic renal cancer is blastic/lytic and survival is
lytic vascular blow out that can bleed
if only 1 with a resectable primary tumour then may be cured
if not 12-18 months
features of benign soft tissue tumour
small size well defined translucent regression in size cystic fluid filled soft lesion
features of malignant soft tissue neoplasm
quick growth systemic symptoms solid lesion large lesions ill defined irregular surface lymphadenopathy
what is a ganglion cyst
herniation of weak portion of synovial joint capsule or tendon sheath
what are the causes of a ganglion cyst and how may it appear
developmental or due to underlying joint damage/arthritis
transilluminate, firm, well defined
what is a bursa
small fluid filled sac lined by synovium around joint to prevent friction
what is bursitis
inflammation of bursa after repeated pressure
true/false - abscesses resolve with antibiotics
false - you need to drain them
what is avascular necrosis and what bones does it affect
ischaemic necrosis of bone
femoral head/condyles, proximal humerous, talar neck, scaphoid
risk factors for avascular necrosis
idiopathic alcohol use steroid use primary hyperlipidaemia thrombophilia sickle cell disease antiphospholipid syndrome decompression sickness
what follows avascular necrosis
secondary OA
primary cancer risk factors
idiopathic
previous radiotherapy
pagets, fibrous dysplasia, multiple echondromas
li fraumeni, familial retinoblastoma
red flags for primary bone malignancy
pain not with movement worse at night swelling/erythema palpable mass fracture systemic symptoms age
when would you see a tumour on x ray
when >50% cortical bone destroyed so get a bone scan, CT, MRI if suspicious
common sites of secondary bone cancer?
BLT with kosher pickle
Breast, lung, thyroid, kidney, prostate
